Mobile bulk material processing apparatus has been developed for a wide variety of applications including the processing of stone, minerals, construction materials and both domestic and industrial waste to generate smaller and/or size categorised aggregate for subsequent processing, use or disposal. For example, in both a quarry or clearance site environment, a mobile crusher is used to crush stone, rubble or site clearance material into smaller pieces. Typically, the crusher is provided with a hopper for receiving the bulk material and a discharge conveyor to transfer the processed and crushed material to a discharge location.
Mobile screening plants also utilise hoppers and discharge conveyors and function to separate the bulk material into one or more screened sized ranges e.g. sand, ballast and aggregate via a screen box unit. Both screening and crushing plants range in size to suit particular applications with smaller self-propelled screening and/or crushing plants being designed to be readily transportable from one site to another on for example a low loader or by being towed as a trailed vehicle. It is accordingly desirable for such processing plates to comprise operating components that can be readily adjusted between an operative (e.g. crushing or screening) mode and a transport mode. As such, a number of mobile processing plants have been proposed having moving components that can be easily adjusted between deployed and transport positions without interfering with one another both in use and during transportation.
Example transportable processing plants with folding or pivoting operative components are described in WO 95/12462; EP 0506812; WO 97/41971; WO 02/26403; WO 2004/018106 and WO 2005/099903.
It is very common for the discharge conveyor (mounted at the sides and rear of the plant) to be foldable or pivotally adjustable between the operative and transport positions to provide a compact unit for transport whilst allowing the plant to stockpile the processed material as far away as possible from the plant main body. WO 2012/110679 and U.S. Pat. No. 3,768,784 disclose distributing conveyor systems that are configured to pivot about a vertical axis to allow the distal end of the conveyor to slew through a wide angle range to allow distributed stockpiling at both the sides and rear of the processing plant. However, such existing apparatus comprises a pivot joint that is mounted below the conveyor which presents problems both during loading of the plant onto a transport trailer and when manoeuvring on site over uneven and rough ground due to the available ground clearance below the pivot joint. Accordingly, what is required is a mobile processing plant that addresses these problems.